Steam player can't find browser credentials

I play CardHunter exclusively through Steam. The two accounts linked to my steam profile are 'Campaign2' and 'Campaign3' -- with Campaign3 being the only one I'm really interested in.

Due to issues with my university's internet I can't play via Steam. I would like to play in-browser. However I have absolutely no idea what my email, username (which is apparently something other than Campaign3), or my password is.

Is there any way I can recover these credentials so I can enjoy CH at school?